Don't seat her in 50B...
There is a big heavy curtain which is pulled around the end of that seats foot stool area to close out the area at the top of the forward staircase, it is very close to the seat, and as people go through it to go too and from the bathrooms, it often gets moved enough to disturb peoples sleep etc. And, it is almost like sitting in a cupboard with a wardrobe to one side and not being able to see the single window which is within 50A seat space... Just don't do it.
I think you will be absolutely fine where you are...
And, yes Background Noise, the new seat, which was unveiled yesterday is a similar design, but the end where the foot stool is, is closed in, and there is a gap between each "pod" of pairs of seats to allow access without stepping over anyones feet.